Endothermic and exothermic reactions

Classify reactions as exothermic or endothermic from the direction of energy transfer, predict the temperature rise or fall observed in the surroundings during each type, and relate the sign of ΔH to each.

Zadania sprawdzające tę umiejętność: 8 Otwórz w wyszukiwarce z filtrami
Zadanie 3aPaper 2, maj 2025, TZ2
wzorowane11 pktobliczeniowetrudne (szac.)

Suppose carbonyl dibromide were made by a free-radical chain reaction of carbon monoxide, CO\ce{CO}, with bromine vapour, BrX2\ce{Br2}, started by ultraviolet light. The questions below treat this hypothetical route with the bond-enthalpy model and the entropy…

Zadanie 23Paper 1A, maj 2025, TZ1
wzorowane1 pktzamknięteśrednie (szac.)

A student stirred 0.030 mol of solid sodium hydrogencarbonate into 40 cm3\mathrm{cm^3} of a 1.0 moldm3\mathrm{mol\,dm^{-3}} solution of ethanedioic acid. HX2CX2OX4(aq)+2NaHCOX3(s)NaX2CX2OX4(aq)+2COX2(g)+2HX2O(l)\ce{H2C2O4(aq) + 2NaHCO3(s) -> Na2C2O4(aq) + 2CO2(g) + 2H2O(l)} The temperature of the solution fell from…

Zadanie 20Paper 1A, listopad 2025, TZ1
wzorowane1 pktzamkniętełatwe (szac.)

The potential energy profile of a reaction is shown. Which reaction has this energy profile? A. ClX2(g)2Cl(g)\ce{Cl2(g) -> 2Cl(g)} B. CaCOX3(s)CaO(s)+COX2(g)\ce{CaCO3(s) -> CaO(s) + CO2(g)} C. NX2OX4(g)2NOX2(g)\ce{N2O4(g) -> 2NO2(g)} D. 2Mg(s)+OX2(g)2MgO(s)\ce{2Mg(s) + O2(g) -> 2MgO(s)}

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